In this Issue September 2006

Want a pet but have asthma?

Australian Asthma Conference 22-25 Oct - "Every Breath Matters"

Low vitamin E intake during pregnancy and asthma for the child

Weight management important to women with asthma

Research Funding Opportunities 

Conference Diary 2006

Want a pet but have asthma?

The National Asthma Council Australia is setting the record straight on pet allergy and provides some survival strategies for pet lovers with asthma.

Eighty per cent of the 2.2 million Australians with asthma have positive allergy test results and it seems pets are the second most common trigger, after the house dust mite.

The family moggie leads the pet allergy trigger list, but other pets such as dogs, birds, rabbits, hamsters, guinea pigs, horses, rats and mice also carry allergens.

“Allergy occurs when a person’s immune system reacts to substances in the environment,” explained National Asthma Council Australia spokesperson, Associate Professor Jo Douglass. “Exposure to an allergen leads to allergic inflammation, characterised by tissue swelling, and symptoms such as hay fever, eczema, hives and asthma.”

Depending on the animal, allergens are found in the saliva, hair, urine or dander (dead skin flakes). These allergens are carried in the air on very small particles. Cat allergen, which mostly comes from cat saliva, is particularly problematic.

“It can remain in the house for months after the cat is removed, invisibly clinging to furniture, walls and ceilings,” Professor Douglass explained.

“It can even be found in places where cats have never lived and it is carried around on clothing. A child could have an allergic reaction at school, simply because the child sitting next to them is carrying cat allergen on their jumper,” she said.

Symptoms may occur within minutes of being exposed to the pet or they may build up over several hours. For some people, a pet allergy can be particularly troublesome, especially in people with life-threatening asthma.

According to Professor Douglass, allergen avoidance can be an effective solution – but, when Fluffy, Bugs or Fido is the unwitting culprit, some tough decisions may need to be made. For the pet, it may mean being avoided, rehoused and even abandoned.

Responsible pet ownership

Each year the RSPCA receives around 133,000 animals that are no longer wanted, including 61,000 dogs and 52,000 cats.  According to RSPCA Australia President, Dr Hugh Wirth, the reasons vary but pet allergy is certainly a factor in some cases.

“Getting a pet in the first place needs to be carefully considered,” he cautioned. “The decision needs to involve the whole family and if there is a suspicion that someone may have pet-triggered asthma or allergy, check it out.

“Spend time with someone else’s animals, perhaps borrow a pet for a few days, and assess the physical reaction before falling in love with a new kitten or puppy that may cause a household member physical distress. Where an allergy is present, consider alternatives such as aquarium fish.

“Certainly, in any situation, surrendering the family pet should be the last option – not the first,” said Dr Wirth.

Professor Douglass sees around five new patients with pet allergy a week in her busy allergy unit at Melbourne’s Alfred Hospital.

“Some accept the advice to remove the pet from the home, but I have many patients who simply won’t part with their pet,” she said.

Pets and asthma research

They are not alone. A 1997 study by Canadian psychologist, Dr Stanley Coren, investigated 341 allergy sufferers who were advised by their doctors to give up their pets to stop allergy symptoms. Only 21 per cent followed doctor’s orders!

In fact, some research has shown that exposure to pets at an early age can decrease the likelihood of children developing asthma. And a recent American study has shown that exposure during infancy to pets or airborne "allergens," such as house dust mites, does not seem to increase the likelihood that a child will develop airway hyperresponsiveness - a hallmark of asthma.¹

The researchers looked for ties between early life factors and airway hyperresponsiveness in a group of 131 children who had at least one parent with a history of asthma or allergies, placing the children at heightened risk for asthma and allergies. However, no relationship was found with early life exposure to perennial aeroallergens or other perinatal and first-year-of-life factors. They concluded that among young children at risk for atopy, sensitization to specific aeroallergens, but not early life exposures, is associated with increased airway responsiveness.

Keeping your pet

A self-professed dog lover herself, Professor Douglass understands the emotional ties and often recommends desensitisation for those unwilling to remove their pet or for people who suffer from occupational pet allergy, such as vets.

This involves a course of 12 to 16 injections at weekly intervals, followed with monthly maintenance injections for two to three years.

“Desensitisation does improve tolerance to furry animals,” Professor Douglass explained. “But, it is not appropriate for everyone. For example, it may be suitable for someone with allergic rhinitis and good lung function, but it is less suitable for someone with chronic, difficult asthma.”

Other coping strategies that are less effective, but may help people and pets cohabit more comfortably, include:

• Move the pet outdoors – provide a secure, warm home outdoors. Consider your pet’s comfort and safety and ensure they are well confined at night for the sake of native animals and birds. If you need to exclude your pet from the home, don’t forget that it is still part of the family. It is essential that it gets plenty of positive contact to keep it from being lonely and bored.

• Keep pets out of bedrooms and living areas – but, be aware that it may take weeks after pet removal before allergens are reduced.

• Vacuum carpets weekly – for the best results, you’ll need a high efficiency particulate air (HEPA) vacuum cleaner.

• Get the facts
  The RSPCA can provide advice on ensuring your pet’s wellbeing, (www.rspca.org.au)
  The National Asthma Council Australia has extensive information to help people manage their asthma (www.nationalasthma.org.au).

1. Tepas EC, Litonjua AA, Celedon JC, Sredl D, Gold DR. Sensitization to aeroallergens and airway hyperresponsiveness at 7 years of age. Chest. 2006 Jun;129(6):1500-8.

Australian Asthma Conference 22-25 October 2006 

"Every Breath Matters"

The Asthma Foundation of South Australia extends to you a cordial invitation to attend the Australian Asthma Conference – “Every Breath Matters”.

From the Welcome reception on Sunday October 22nd 2006 to the closing session on Tuesday October 24th, this conference promises to be an opportunity to learn, share, network and contribute.

The theme “Every Breath Matters” draws attention to the ongoing burden of asthma and related respiratory illnesses where there is still so much to learn.

Program highlights include presentations from a selection of eminent speakers including:

• Professor Peter Sly
  University of Western Australia and Princess Margaret Hospital
   
• Dr Sandra Anderson
  World authority on exercise-induced bronchoconstriction,
   
• Dr Karl Kruszelnicki
  Scientist and media personality, and
   
• Associate Professor Guy Marks
  Woolcock Institute of Respiratory Medicine.

For further information, please visit the dedicated conference website:
www.aomevents.com/conferences/AAC or email conference@aomevents.com. 

Low vitamin E intake during pregnancy and asthma for the child

Minding an infant's diet after birth may have an influence on children who may be genetically predisposed to asthma, as discussed in the evidence-based information paper Asthma and Diet in Early Childhood: A guide for health professionals.

Recent research from the UK now suggests that the mother's diet may also have an influence as children whose mothers had a low intake of vitamin E during pregnancy were more likely to develop wheezing and asthma by age five.²

Over a five-year period, Dr Graham Devereux and seven associates from the University of Aberdeen, assessed maternal nutrient and respiratory status in 1,253 mothers and children.

According to the authors, children born to mothers from the lowest quintile of vitamin E intake were over five times more likely to manifest early persistent asthma than children whose mothers were in the highest quintile.

Their findings suggest that vitamin E has a dual effect on lung function and airway inflammation and that the effects could change at differing periods of prenatal and early life, according to Dr Devereux. Lung function was associated with early vitamin E exposure independent of atopy, whereas allergic airway inflammation was associated with vitamin E exposure in later pregnancy.

However, the researchers also noted that the airways are fully developed by 16 weeks after conception and, consequently, vitamin E exposure in early pregnancy may be more likely to influence airway function than exposure later in pregnancy.

The study also suggested that children's own nutrient intake at the age of five did not modify the associations between maternal nutrient intake and respiratory outcomes in the children. 

Vegetable oils (sunflower, rapeseed and corn), margarine, wheat germ, nuts and sunflower seeds were cited as major food sources of vitamin E for mothers in the U.K.

In a prior report on this group of children, the researchers found that two-year-olds whose mothers' vitamin E intake during pregnancy had been relatively low were more likely to wheeze even when they had no cold.

For the previous study, the investigators recruited 2,000 pregnant women at 12 months gestation who were attending area antenatal clinics between 1997 and 1999. Plasma antioxidant concentrations were measured in 1,856 mothers at 12 weeks gestation. In addition, symptom questionnaire data was later obtained for 1,253 children. From that group, 478 children were able to provide a lung function test measurement.

In light of the new findings, the authors concluded that the relationship shown between mothers' vitamin E intake during pregnancy and the respiratory outcomes of their children were likely "underestimates of the true association."

While the researchers noted that vitamin E supplementation in adults with established asthma has not been shown to be of clinical benefit dietary modification or supplementation during pregnancy to reduce the likelihood of childhood asthma warrants further investigation. .

Reference

2. Devereux G, Turner SW, Craig LC, McNeill G, Martindale S, Harbour PJ, Helms PJ, Seaton A. Low maternal vitamin E intake during pregnancy is associated with asthma in 5-year-old children. Am J Respir Crit Care Med. 2006 Sep 1;174(5):499-507

Useful Resources

Asthma and Diet in Early Childhood: A guide for health professionals

Asthma and Wheezing in the First Years of Life: A guide for health professionals

Weight management important to women with asthma

A recent Canadian study shows that obese, non-allergic women are at a greater asthma risk than their male-counterparts.³

Researchers from the University of Ottawa administered a survey to over 85,000 people that included questions about self-reported asthma, allergy history, height, and weight.

After controlling for covariates, results showed that obese women had an 85 percent increase in the risk of asthma, compared with women at a normal weight. Obese men had a 20 percent increase in the likelihood of asthma, compared with men at a normal weight.

One unit of increased body mass index (BMI) was associated with an increased asthma risk of 6 percent in women and 3 percent in men.

The study also found that obese, non-allergic women showed a 9.5 percent asthma risk, while their normal-weight counterparts showed only a 3.1 percent risk. Researchers concluded that obesity is likely to have a larger effect on nonallergic asthma. The greater prevalence of nonallergic asthma in women may explain the stronger obesity-asthma association seen in women compared with men and children, who have a greater prevalence of allergic asthma.

Reference

3.  Chen Y, Dales R, Jiang Y. The Association Between Obesity and Asthma Is Stronger in Nonallergic Than Allergic Adults. Chest. 2006 Sep;130(3):890-5

Research Funding Opportunities